Edger and feed system therefor

ABSTRACT

An edger for applying a shaped layer of viscous material to a workpiece as the latter is fed along a roller table by a powerdriven mechanism, the edger having a guide surface engaging the edge to be coated, a troweling element downstream from the guide surface, and an orifice for applying the material in advance of the troweling element. Spring-loaded, resiliently yieldable sealing elements on opposite sides of the gap into which the material is fed receive the edge with an interference fit. In one form, the seals are generally parallel spring strips, and in another, they are spring-loaded blocks of wear resistant material. The edger has a movable section shifted by the leading end of the workpiece into an operating position to open a normally closed flow valve controlling the flow of edging material through the orifice, and the pumping unit for the edging material is a pressurized tank for receiving a can of material and having a pressure pad pressed against the material by the actuating rod of an air cylinder and by direct air pressure to force material out of the tank through a wand. A gum rubber disk seals around the can and the wand, and a special air passage in the actuating rod assists in removing the pad from the can.

Unite States atent [191 Tuberman 1 EDGER AND FEED SYSTEM THEREFOR [75] Inventor: Arthur H. Tuberman, Lawndale,

Calif.

[73] Assignee: Arthur H. Tuberman, Lawndale,

Calif.

[22] Filed: Mar. 19, 1971 [21] Appl. No.: 126,205

[52] US. Cl. 118/3, 118/410 [51] Int. Cl. BOSc 5/02 [58] Field ofSearch 118/410,41l,4l5, 2,413,

Primary Examiner-John P. McIntosh Attorney, Agent, or Firm-Fulwider, Patton, Rieber,

Lee & Utecht [451 Apr. 30, 1974 [57] ABSTRACT An edger for applying a shaped layer of viscous material to a workpiece as the latter is fed along a roller table by a power-driven mechanism, the edger having a guide surface engaging the edge to be coated, a troweling element downstream from the guide surface, and an orifice for applying the material in advance of the troweling element. Spring-loaded, resiliently yieldable sealing elements on opposite sides of the gap into which the material is fed receive the edge with an interference fit. In one form, the seals are generally parallel spring strips, and in another, they are springloaded blocks of wear resistant material. The edger has a movable section shifted by the leading end of the workpiece into an operating position to open a normally closed flow valve controlling the flow of edging material through the orifice, and the pumping unit for the edging material is a pressurized tank for receiving a can of material and having a pressure pad pressed against the material by the actuating rod of an air cylinder and by direct air pressure to force material out of the tank through a wand. A gum rubber disk seals around the can and the wand, and a special air passage in the actuating rod assists in removing the pad from the can.

- 26 Claims, 17 Drawing Figures EDGER AND FEED SYSTEM THEREFOR BACKGROUND OF THE INVENTION This invention relates to the application of viscous edging material such as plastic or putty to an edge of a workpiece such as particleboard, a sheet of plywood, or other material, to fill imperfections in the edge and apply a finished coating layer to the edge.

Such coating layers have been applied in the past with machines for feeding successive workpieces along a preselected path relative to an edger for engaging the edge to be coated, applying the edging material to the edge, and smoothing the edging material to the desired contour for the finished layer by wiping or troweling the material after it has been applied. Usually, the finished coating is a thin and slightly rounded strip which adheres to the coated edge and merges smoothly with the margins of the edge at the corners of the workpiece constituting the opposite boundaries of the edge. The coating may be applied, however, in a variety of contours.

Each workpiece typically is guided on a table and along an adjustable fence which determines the path followed by the workpiece, and the edger is provided with a guide surface for sliding along the edge to be coated and thus insuring that the edger and the workpiece are in a preselected relation during the coating operation. A trowel element is spaced downstream from this guide surface, and the viscous material is applied in advance of the trowel element to be smoothed and shaped as the workpiece passes the trowel element.

Although such prior machines have accomplished the desired purpose in a generally satisfactory manner, problems have existed in properly controlling the edging material, particularly along the sides of the troweling element and after prolonged periods of service use during which wear on the edger can occur, resulting in a tendency toward leakage. Also, variations in thickness, configuration, and position of the workpiece accentuate leakage problems, and the result in many instances has been an imperfect finished product.

The feeding of the edging material to the edger also has presented problems because of the intermittent nature of the operation. A pumping unit typically is provided to force the material into contact with the workpiece, and the flow of edging material must be controlled, between workpieces, to prevent feeding when no workpiece is passing the edg er. This necessitates careful attention to the activation and deactivation of the pumping system, either with an intermittently operating pump or with a control valve for turning the flow on and off. In presently available equipment, the activation and deactivation are accomplished manually.

It should be noted that the edging materials in use are highly abrasive and also dry or set quickly upon exposure to air. For these reasons, the handling of the materials is a difficult matter, and flow controls using fine metering orifices and the like cannot, practically, be used. Moreover, clean-up between periods of use can be a bothersome and time-consuming problem.

In addition, conventional pumping units for this type of material are less than fully satisfactory, typically involving the use of dangerously high delivery pressures, producing surges in the flow of edging material to the edger, being subject to channeling of the edging material in supply containers, and involving time-consuming and messy handling operations with respect to the edging materials.

SUNIMARY OF THE INVENTION The present invention resides in an improved edger and feed system for avoiding, or at least minimizing, the foregoing disadvantages and producing an improved finished product in a more troublerfree and reliable manner. In general, this is accomplished by improving the sealing characteristics of the edger to accommodate variations in the thickness, configuration and position of the workpiece being edged without loss of control of the edging material, and to reduce the adverse effects of abrasive wearing of parts of the edger so as to increase the effective service life of the edger; by more effectively controlling the flow of edging material in a novel and simple manner in response to the movements of the workpieces relative to the edger; by simplifying the disassembly of the edger for cleaning; and by providing an improved pumping unit cooperating with the edger to feed edging material with a uniform flow and without the many disadvantages of prior pumping units for the same general purpose.

More specifically, a primary feature of the invention is the provision of yieldable, spring-loaded sealing elements along opposite sides of the troweling element for receiving the workpiece with an interference fit and remaining in tight sealing engagement despite irregularities in the workpiece, even after prolonged periods of use, without'leakage of the edging material that can produce imperfections in the finished product. In the presently preferred form of the invention, the sealing elements are spring strips disposed on opposite sides of the path of the edge to be coated, and tightly but slidably engageable with the sides of the work along opposite sides of the gap intolwhich the edging material is fed. The troweling element extends across the space between these spring strips, and is either formed integrally therewith or is a separate piece independently supported on the edger.

In another form, the sealing elements are wearresistant blocks disposed on opposite sides of the gap and having beveled edges for engaging the corners of the workpiece along opposite sides of the edge to be coated. These blocks are urged toward the path of the I work and into an extended position by springs which yield as the workpiece engages the blocks and thereafter press the blocks into tight sealing engagement with the workpiece. The springs and the blocks are held by movable retainers which permit adjustment of the extended position.

Another important feature of the edger is the automatic feed control of the edging material in response to engagement and disengagement of workpieces with the edger. For this purpose, the edger has a movable section that is engageable with the workpiece as it approaches, and is movable in response to such engagement from a ready position to an operating position,

automatically opening a control valve in the edger during such movement, and thereafter closing the control valve by reverse movement after the workpiece has passed. The movable section is mounted on a fixed base section in a novel manner to effect opening and closing yieldably urged toward the workpieces so as to remain in contact therewith despiteirregularities such as waviness in the edge to be coated.

Still another aspect of the invention resides in the construction of the pumping unit to produce a reliably uniform flow of edging material without surges, and without need for dangerously high feeding pressure. To these ends, the pumping unit comprises a pressurized tank for receiving a can of the edging material bodily inside the tank, and a novel pressure-pad feeding arrangement which seals the contents of the can against exposure to air while effectively producing a uniform flow of the material from the can, upon demand, and without danger of channeling of air through the material, surging, hardening or other adverse effects.

Other objects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of an edging machine equipped with an edger and pumping unit embodying the novel features of the present invention, shown with a workpiece being guided and fed toward the edger and about to engage the latter;

FIG. 2 is an enlarged, fragmentary cross-sectional view taken substantially along the line 22 of FIG. 1;

FIG. 3 is an enlarged fragmentary cross-sectional view taken substantially along the line 33 of FIG. 1, and partly broken away for compactness of illustration;

FIGS. 4-7 are enlarged fragmentary perspective views of workpieces showing different edge contours that may be applied with the edging machine and variations thereof;

FIG. 8 is an enlarged, fragmentary plan view of the edger in FIG. 1, taken within the are 8 thereof, with parts broken away and shown in cross-section;

FIG. 9 is a view generally similar to FIG. 8, with parts in moved positions;

FIG. 10 is a fragmentary plan view of the edger in FIG. 9, shown partly in cross-section;

FIG. 11 is a fragmentary cross-sectional view taken substantially along line 1l11 of FIG. 9;

FIG. 12 is a perspective view of the sealing and troweling elements of the edger in- FIGS. 8 11;

FIG. 13 is a perspective view similar to FIG. 12 but showing an alternative form of the sealing and troweling elements;

FIG. 14 is a fragmentary view similar to part of FIG. 11, but showing the alternative form of FIG. 13;

FIG. 15 is a fragmentary view similar to part of FIG. 9, but showing another alternative form;

FIG. 16 is a fragmentary view similar to FIG. 15, but

showing still another alternative form; and

FIG. 17 is a fragmentary cross-sectional view similar to FIG. 1 1 but showing the alternative form of FIG. 16.

DETAILED DESCRIPTION ter is fed along a predetermined path on a supporting table 14. The table, which may be of various conventional types, herein comprises a pair of spaced, parallel side rails 15 and 17 rotatably supporting a series of parallel rollers 18 having upper surfaces in a common horizontal plane, as shown in FIG. 2, and has a vertical guide member or fence 19 positioned along one side of the workpiece path with an upright positioning surface 20 for sliding engagement with the edge 12 to be coated.

To feed the workpiece 13 along the table 14 while holding it against the fence 19, a power-driven feed mechanism 21 is positionedabove the table, as shown in FIGS. 1 and 2, and has a plurality of feed rolls 22 which are supported on a vertically adjustable frame 23 for engagement with the upper surface of the workpiece 13 resting on the supporting rollers 18. The feed rolls 22 are supported on parallel shafts 24 that are driven by a motor 25, counterclockwise as viewed in FIG. 2, and are inclined relative to the path of the workpiece moving along the table so as to urge the workpiece laterally toward the fence 19 as well as downstream (to the right in FIGS. 1 and 2) along the table 14 and past an edger 27 that is mounted on the table adjacent the downstream end of the fence 19.

As the edge 12 of the workpiece 13 moves past the edger 27, edging material in semi-fluid, viscous form from a pumping unit 28 alongside the table 14 is supplied to the edger through a conduit 29, and is applied to the edge as a relatively thin coating layer for filling voids and imperfections in the workpiece. The edger also wipes and trowels the coating material to a uniform and smooth, finished form having the desired contour for the finished edge, which then has the appearance of an edge of higher quality material such as solid, natural wood. The edge then may be painted or stained, as desired, after the layer of coating material has set in the desired shape.

Representative contours that may be applied are illustrated in FIGS. 4-7, wherein it can be seen that the coating layer preferably follows the contour of the edge that has been coated, and merges smoothly with the side surfaces of the workpiece along the opposite margins of the edge, that is, at the spaced corners constituting the opposite sides of the edge. In FIG. 4, the coating layer 11 has a slightly rounded surface that tapers in thickness toward each side and is applied to an edge 12 that is perpendicular to the sides of the workpiece,

while in FIGS. 5, 6 and 7, layers 11a, 11b and are applied to special'edge contours on workpieces 13a, 13b and of types that might be used on cabinet doors. It is to be understood, however, that these contours are shown for purposes of illustration only, and

' that other contours also are within the scope of the invention.

As previously mentioned, coating layers of this gen- I eral type have been applied in the past with machines of the foregoing general character, using edgers that are generally similar in principles of operation to the edgers of the present invention. Basically, such edgers have included a'base 30 (see FIG. 9) mountable alongside the workpiece path, a guide surface 31 for engaging the edge 12 to be coated in advance of, or upstream from, the application of the edging material, and thus in the same plane as the edge and the positioning surface 20 of the fence 19, a troweling element 32 spaced downstream from the guide surface 31 and outwardly away from the edge 12 to be coated to form a specially shaped gap 33 between the edge and the troweling element, and an orifice 34 between the guide surface and the troweling element for the application of edging material in viscous, semi-fluid form to the edge, in advance of the troweling element.

The edging material is fed through the orifice 34 by the pumping unit 28 and forced against the passing portion of the edge 12 to adhere thereto and be carried thereon through the gap 33 as the edge travels past the troweling element 32. Thus, the edging material is wiped and smoothed to the desired shape by the troweling element, and thereafter dries and sets in that shape as a finished edge coating 11.

In accordance with a primary aspect of the present invention, two spring-loaded sealing elements 35 are mounted on opposite sides of the gap 33 to receive the edge 12 of the workpiece 13 between them with an interference fit, and to yield resistably away from their normal positions to accommodate the workpiece while remaining in tight sealing engagement therewith, thereby more effectively controlling the edging material as it is troweled to the desired shape. Because the sealing elements are yieldable and spring loaded, they maintain an effective seal on each side of the gap 33 despite irregularities in workpiece. thickness, configuration and position, and retain their sealing effectiveness as wear occurs on the sealing surfaces after prolonged periods of service use.

With specific reference to FIG. 9, the preferred embodiment of the edger 27 shown therein has a base 30 in the form of a plate that is secured to the rail 17 alongside the path of the workpiece 13 to be edged, and also has a generally rectangular body 37 supported alongside the base with an inner side 38 of the body positioned alongside the path along which the edge 13 moves as the workpiece is moved along the table 14. This inner side of the body parallels, and is spaced from, the path of the edge, as determined by the positioning surface of the fence l9, and a tongue 39 projects inwardly from the inner side of the body to engage the edge 12, thus locating the edger and the edge relative to each other during the edging operation. This tongue has the guide surface 31 on its inner end, and preferably has a front surface that is inclined inwardly and downstream relative to the path of the workpiece and joins the guide surface 31 with a slight radius. It will be evident that the guide surface is disposed in the same plane as the positioning surface 20 of the fence 19, both being pressed against the workpiece edge 12.

The outlet orifice 34 for the edging material is formed in the body 37 beyond (downstream from) the guide surface 31, and herein has an upstream side that is formed by a surface 40 of the tongue generally parallel to the front surface thereof, and thus inclined toward the workpiece and downstream relative to the direction of workpiece trowel. The downstream side of the orifice is formed by a rounded shoulder 41 of the body which curves inwardly toward the edge 12 and to the right, or downstream, away from the tongue 39, to cooperate with the latter in defining a relatively narrow slot opening toward the workpiece. The downstream side of the slot formed by the shoulder 41, however, is a relatively narrow surface that is spaced outwardly relative to the guide surface 31 and the edge 12, to form the upstream or entry end of the gap 33.

It will be seen in FIG. 9 that the orifice 34 is at the end of a supply passage 42 extending through the body 37 and inclined first upwardly to the left, as viewed in FIG. 9, and then turning back to the right toward the orifice, the effective flow area being progressively restricted toward the orifice. The passage as defined in a block constituting the body 37, and the tongue 39 preferably is one end portion of a separate strip 43 that is fitted against the inner side of the block and held in place by a screw 44.

As shown most clearly in FIG. 11, the opposite sides of the body 37 are recessed at 45 to reduce the thickness of the body adjacent the inner side (the right side in FIG. 11), and the sealing elements are two flat spring stips which normally are disposed in two generally parallel planes determined by the bottom surfaces of the two recesses. Side plates 47 shaped to fit into and substantially fill the recesses are secured to the body by screws 48 which are threaded into the body through holes 49 in flanges 50 on the spring strips. Thus, the side plates 47 anchor the strips to the body with sealing portions of the strips projecting away from the body in properly spaced, parallel relation.

The strips 35 project inwardly from the body 37 and straddle the workpiece 13, as shown in FIG. 11, in sealing engagement with the opposite flat sides of the workpiece along the edge 12 to be coated. Preferably, these strips extend longitudinally of the workpiece from a point upstream from the tongue 39 to the downstream end of the troweling element 32. Thus, the spring strips are positioned to seal against the workpiece along the entire operating zone in which the coating material is to be controlled.

As has been stated, the spring strips 35 are more closely spaced than the thickness of the workpiece 13 to be edged, so as to receive the workpiece with an interference fit. To facilitate entry of the workpiece between the strips, the upstream ends of the strips are inclined away from each other at 51 and are flared to a spacing greater than the thickness of the workpiece, as shown in FIGS. 10 and 12, thus forming a wide entry mouth. The troweling element 32 is disposed between the strips 35 beyond the entry end of the gap 33, and

has opposite sides that are positioned closely adjacent the strips along the opposite sides of the gap.

The troweling element 32 may take various forms,

' including simply a shaped surface of the body 37 constituting a continuation of the shoulder 41. In the preferred embodiment, however, the sealing strips 35 and the troweling element 32 are formed integrally as parts of a single sheet of spring material which is shaped and bent into a special assembly, shown most clearly in FIG. 12. In this assembly, the troweling element 32 integrally joins the lower edges of the downstream portions of the spring strips to form a U-shaped channel on one end of the assembly, and the flanges 50 project I downwardly (FIG. 12) from the portions of the strips that project beyond the retaining plates, upstream from the channel. Horizontal slits 52 between the flanges and the projecting portions of the strips facilitate the flaring of the strips to form the entry mouth. The holes 49 are formed in the flanges to receive the screws 48.

bending the unsevered portion of the sheet into the channel. The lower edges 53 and ends 54 of the flanges 50, and the adjacent edge 55 of the channel, constitute the lines originally formed by the T-shaped cut. The formation of the slits 52, the holes 49, and the associated flared ends 51 are the only additional operations needed. The illustrative troweling element is of shallow concave curvature for forming an edge as in FIG. 4.

The body 37 has a clearance notch 57 (see FIG. 9) receiving the troweling element 32 and having an end wall 58 against which the troweling element abuts, as shown in FIG. 9. The sealing strips 35 are pressed tightly against the sides of the tongue 39 and also are clamped against the bottoms of the recesses 45 on both sides of the body by the retaining plates 47, but are free to yield away from each other beyond the inner edges 59 (FIG. 11) of the retaining plates. These inner edges are spaced from the inner side of the body, so the spring strips are free to yield resiliently at the level of the edge 12 of the workpiece 13, as shown in FIG. 11.

With the foregoing arrangement, the leading end 60 of the workpiece 13 approaching the edger 27 enters the flared mouth of the spring strips 35 and forces the strips apart in passing through the mouth. The workpiece then engages and slides across the guide surface 31 while the spring strips remain pressed tightly against its opposite sides, as a result of the resilience of the spring material. Edging material is forced through the orifice 34 into the gap 33 and against the edge 12 of the workpiece, in advance of the troweling element 32, to coat the edge with a layer of the material.

As the edge 12 moves across the troweling element 32, the edging material is pressed against the edge while being smoothed and shaped to the desired contour, as shown in FIG. 11. The edge layer remains in this contour after the workpiece has passed the troweling element, and thus dries and sets on the workpiece as a finished edge coating. The material also fills any knicks or saw tears along the corners, and maintains the desired coating thickness even after prolonged use that would wear and variation in thickness in conventional edgers.

The alternative form shown in FIGS. 13 and 14 is the same in all important respects as the form shown in FIGS. 9 through 12, except that the troweling element gral with the spring strips, and the entire assembly may be retained in place by a single screw 44.

The last alternative form shown in FIGS. 16 and 17 illustrates another of the various ways in which two sealing elements 81 may be supported on the edger and spring-loaded into yieldable, sealing engagement with a workpiece, together with minor variations in the guide surface 82 and the troweling element 83. In this instance, the guide surface 82 is on a tongue 84 that is formed integrally with a thickened plate 85 bolted, as before, to a body 87 in which a supply passage 88 is defined, one side 89 of the passage adjacent the orifice 90 being formed by a surface of the tongue plate 85 and the opposite side by a surface 91 leading to a rounded shoulder 92 spaced inwardly (downwardly as viewed in FIG. 16) from the level of the guide surface 82. The troweling element 83; is simply a shaped surface (herein concave) of the body 87 and terminates at a right-angle ledge 93.

The sealing elements 81 are small, generally rectangular blocks of wear-resistant material such as carbide, having flat sides 94 disposed against and slidable along the opposite sides of the edger body 87 and projecting inwardly beyond the troweling element (to the right in FIG. 17) to lie on opposite sides of the gap between the troweling element and the workpiece edge 12 to be coated. Each sealing block is slidably mounted between the body and a retainer 95 that is adjustably secured to the body and formed with a detent lip 97 for engaging the inner end 98 of the sealing block to limit the amount of movement of the sealing block inwardly toward the workpiece.

Coiled springs 99 (FIG. 17) are confined in chambers 100 in the retainers 95 and are preloaded and compressed between the latter and the sealing blocks 81 to urge the blocks toward inwardly extended positions determined by the detent lips 97. A bolt 101 is inserted through ahole 102 in one retainer and a clearance passage 103 in the body 87, and is threaded into a tapped hole 104 in the other retainer so that the retainers may be clamped together and against the opposite sides of the body with the detent lips 97 in different selected 61 is a separate strip of sheet material that is bent to the desired shape and independently supported between two spring strips 62 that are generally rectangular in shape. The troweling element is secured as by brazing or spot-welding at 63 to a mounting block 64 that fits between the spring strips in a notch 65 in the body 67, similar to the notch 57 in FIGS. 9 and 11. The spring strips are held by screws 68 and retaining plates 69, and have portions 70 that are inclined away from each other at the entry end to form a flared mouth. The free edges 71 of the troweling element fit snugly against the spring strips, and the upstream edge 72 of the element abuts against a wall 73 similar to the wall 58 in FIG. 9.

Another alternative form, shown in FIG. 15, is quite similar to the form in FIGS. 13 and 14, except that the tongue 74 is formed by a piece of sheet material integral with the sheet material used for the spring strips, and the troweling element 75 is laid directly on a continuation 77 of the orifice shoulder 41 with a bent-over portion 78 which cooperates with the tongue in defining the orifice 79. This troweling element also is intepositions providing different extended positions of the sealing blocks 81 relative to the path of the workpieces. The downstream side of each block bears slidably 1 against a lug 105 (FIG. 16) projecting inwardly from the body 87 beyond the ledge 93, one lug being provided for each sealing block and being separated from the other lug by a space through which the workpieces can pass.

As shown in FIG. 17, the adjacent sides 94 of the sealing blocks 81 thus form the sides of the gap into which edging material is forced. The inner ends of the blocks are formed with beveled edges 107 for engaging the corners of workpieces, and the upstream sides of the blocks are rounded at 108 to form a flared entry end or mouth for receiving the workpiece and camming the sealing blocks out of the extended positions and into partially retracted positions, against the forces exerted by the springs 99.

The partially retracted positions are shown in FIG. 17, wherein it will be seen that the sealing blocks 81 remain tightly pressed against the corners of the workpiece 13 on both sides of the gap to seal the edging material therein. For optimum sealing, the angle of each bevel 107 with the plane of the adjacent side 94 of the associated block should be 30or less, and preferably about 20.

With this arrangement, each workpiece l3 enters the edger as before, and slides along the guide surface 82 into engagement with the rounded upstream sides 108 of the sealing elements 81, which are more closely spaced than the thickness of the workpiece. As a result of this interference fit, the rounded sides and the leading end of the workpiece cooperate to depress the sealing blocks away from the detent lips 97 until the space between the beveled edges 107 is sufficient to admit the workpiece between the sealing blocks, such depression of the sealing blocks occuring almost instantaneously as the leading end of the workpiece enters the edger.

Thereafter, the springs 99 continue to urge the sealing blocks 81 toward the workpiece 13, holding the beveled edges 107 in tight sealing engagement with the corners of the workpiece on opposite sides of the gap until the full length of the workpiece has passed through the edger. Thus, the sides of the gap remain sealed to control the edging material in the gap, and the sealing blocks cooperate with the troweling element in imparting the desired shape to the coating layer.

Another important aspect of the invention is the novel manner of initiating the flow of edging material through the edger as each workpiece 13 approaches the edger, and terminating the flow as the workpiece leaves the edger. For these purposes, the edger is formed in two sections, one secured to the rail 17 in a fixed position along the workpiece path and the other movably mounted on the fixed section and yieldably positioned to be engaged by approaching workpieces and moved from a ready position to an operating position by the workpiece itself. As an incident to this movement, a valve 110 controlling the flow of edging material to the orifice and the gap is opened to admit edging material into the supply passage, and after each workpiece has passed, the valve is closed by return of the movable section to the ready position.

As shown most clearly in FIGS. 8 and 9, the movable section of this form of the edger is the body 37 which has the sealing and troweling elements mounted on its inner edge, facing toward the path of the workpiece 13, and the supply passage 42 internally formed in the body. This passage opens through a convex arcuate surface 111 on another side of the body, the lower right side as viewed in FIG. 8.

The fixed section of the edger is the base 30, which is disposed alongside the movable section and is secured to the rail 17. A block 112 is fastened to the base by two screws I13 and is positioned to project laterally from the base across the lower right side of the movable section as viewed in FIGS. 8 and 9. This block has a concave arcuate surface I 14 that is .complementary to the convex surface 111 of the movable section, and is disposed alongside the latter in closely spaced relation therewith, preferably with a slight clearance between the surfaces on the order of 0.0005 to 0.0025 of an inch.

To support the movable section 37 on the fixed section 30, a pin 115 is fastened to the fixed section and extends laterally therefrom through a bore 117 in the movable section with a snug but rotatable fit, a bushing 1 18 being telescoped over the pin for free relative rotation of the parts. Thus, the movable section can rock about an axis defined by this pin. The arcuate surfaces 111 and 114 are coaxial with the movable section (that is, curved about the pivotal axis) so as to remain in the same closely spaced relation during a range of rocking movement of the movable section.

The valve 110 for controlling the flow of edging material through the supply passage 42 comprises a pair of ports 119 and 120 formed in the two arcuate surfaces 11 1 and 1 14, respectively, to be misaligned in one angular position of the movable section (the ready position shown in FIG. 8) and aligned in another angular position (the operating position in FIG. 9). The port 119 opens from the convex surface into the supply passage 42, and the port 120 communicates through the block 112 with the conduit 29 leading to the pumping unit 28. Thus, the flow of edging material through the ports is blocked in the ready position, but when the movable section 37 is in the operating position, the ports communicate with each other to connect the pump conduit to the supply passage and thus to the orifice 34.

To hold the movable section 37 normally in the ready position (FIG. 8) with the valve 110 closed, a spring 121 is fitted in a blind bore 122 opening through the lower left side of the movable section, and is compressed between the closed right end of the bore and a pin 123 which extends through the opposite end portion of the bore, parallel to the pivot pin 115.

This pin 123 is fastened to the base section 30 so that the spring 121 acts between the two sections to urge the movable section 37 counterclockwise relative to the fixed section. A plug 124 is fast in the open end of the spring bore and is formed with a notch 125 which receives the pin 123. An aligned and similarly shaped groove 126 in the block 37 serves as a stop for limiting the counterclockwise rocking of the movable section in the ready position shown in FIG. 8.

In this position, the tongue 39 is disposed across the path of the workpiece to be edged, and thus is positioned to be engaged by each approaching workpiece and cammed downwardly (as viewed in FIG. 8) out of the path. It will be seen that this motion of the tongue rocks the movable section 37 from the ready position to the operating position, against the yieldable force of the spring 121, so as to open the valve 1 10 and initiate the flow of edging material through the supply passage 42 to the orifice 34.

While the workpiece 13 remains in contact with the guide surface 31 of the tongue 39, the spring 121 continues to press the tongue tightly against the workpiece valve is, in the preferred embodiment shown herein, rocking motion about the pin 115. The tongue 39 serves as an actuator that is responsive to the approach of workpieces 13 to open and close the valve at the proper times, in cooperation with the spring 121 for continuously urging the movable section toward the ready position.

It is to be noted that this configuration of the edger makes it possible to remove the movable section 37 for cleaning or replacement simply by slipping it laterally off the two pins 115 and 123 and away from the base section 30. This also makes it possible to store the movable section in solvent between periods of use, to prevent hardening of edging material that is inside the supply passage 42. The clearance between the arcuate surfaces 111 and 114 is small enough to prevent any appreciable leakage of typical edging materials between the sections, while being large enough to avoid binding of the two sections or excessive abrasive wearing of the arcuate surfaces thereof.

Although the valve arrangement has been described only in connection with the embodiment of FIGS. 8 and 9, elements of the arrangement also are shown in FIGS. 15 through 17, and the same reference numbers are used to indicate corresponding parts in these views.

The improved pumping unit 28 is shown in detail in FIG. 3, and includes an outside pressure tank formed by a cylindrical sidewall 130, a cover 131 secured across the open end of the sidewall by three clamps 132 (one shown in FIG. 3) and sealed by a gasket 133, and a bottom wall 134 supported above a dome-shaped lower end wall 135 and braced by filler material 137 in the lower end portion. A stand 138 receives the lower end portion of the tank to support the latter in an upright position.

Inside the tank is an open-ended container 139 for holding the bulk edging material 140 to be pumped to the edger, this container typically being a gallon can of a type commonly used in the trade and having a downwardly tapering sidewall and a closed lower end wall resting on the bottom wall 134 of the tank. The can is sized to fit freely in the tank with clearance below the cover 131 and between the can and the sidewall 130 of the tank, as shown in FIG. 3. Thus, when the cover has been removed, a fresh can of edging material can be placed in the tank in the position shown, which is offset from the center of the tank to provide room for swinging of the handle 141 of the can. An eccentric ring 142 is placed on the bottom wall 134 to define a positioning recess 143 for receiving the lower end of the can. 1

An elongated tube 144 extends downwardly into the can from a fitting 145 on the cover, and has an open lower end submerged in the edging material 140 close to the lower end of the can. This tube forms a so-called wand through which edging material can flow upwardly from the can through the cover 131 and the fitting 145 to the conduit 29 leading to the edger. With the wand fixed to the cover, it is inserted into and removed from the can as an incident to the covering and uncovering of the tank.

To force the edging material 140 out of the can 139 through the wand 144, a pressure pad 147 is fitted into the top of the can with the wand projecting through an opening 148 in the pad, which has a flexible annular seal 149 for yieldably engaging the wand, and a larger but similar seal 149a engaging the sidewall of the can. This pad is pressed downwardly against the edging material with sufficient force to cause the edging material to flow upwardly into and through the wand.

The downward force on the pad 147 is developed by the combined effect of gas under pressure, preferably air, in the tank around the can 139 and above the pressure pad 147, and of a downward force applied to the pressure pad through an actuating rod 150 extending upwardly through a sealed opening in the cover 131.

As shown in FIGS. 1 and 3, the air under pressure is introduced into the tank through a line 151 from a suitable source (not shown), connected through a pressure regulator and control 152 to an inlet fitting 153 on the cover. In addition, air flows upwardly from the inlet fitting through a tube 154 that is connected to, and opens into, the upper end 155 of a pneumatic cylinder 157 mounted on top of the tank, and the actuating rod 150 extends into this cylinder and carries a piston 158 which reciprocates within the cylinder. The lower end portion of the cylinder is vented to atmosphere at 157.

With this arrangement, the pressurized air in the cylinder 157 above the piston 158 develops a downward force on the actuating rod 150 for holding the pad 147 in contact with the edging material, as the air pressure acts through the pad to force the material upwardly through the wand 144. The pressure pad 147 serves to prevent drying contact of the air in the tank with the edging material 140 in the can, while wiping the inside of the can reasonably clean and preventing localized flow, or channeling, of air through the edging material.

When the cylinder 157 and tank are pressurized, the force on the pressure pad 147 is uniform and the flow through the wand 144 to the edger also is uniform, thus eliminating pressure pulses that have been inherent in prior pumping units for handling this type of material. The seals 149 and 149a preferably are formed by a disk of pure gum rubber that is clamped between two metal plates fast on the end of the rod 150, and are held in yieldable sealing engagement with the wand and can by the air pressure in the tank. Pure gum rubber is the preferred material because it is resistant to the deleterious effect of the solvents in the edging material, and maintains effective seals over prolonged periods of service use.

An important advantage of this pumping unit 28 is the fact that it is made up of readily available or easily fabricated components, yet has the several operational features previously mentioned. In addition, it eliminates the need for pouring or otherwise handling the edging material, since the cans in which such material is supplied serve to hold the material in the tank.

In preparing the unit for operation, the air pressure is bled off at the regulator 152, and the cover 131 is removed and an open can 139 of edging material is positioned in the tank. Then the pressure pad 147 is placed in the can with the opening 148 positionedto receive the wand 144, and the cover is replaced and clamped on the can with the wand projecting through the pressure pad, as shown.

When the air pressure is turned on, both the inside of the tank and the upper end portion 155 of the cylinder 157 are pressurized to press the pad 147 downwardly against the edging material 140. The air pressure outside the can counterbalances part of the force developed on the can, and thus avoids the development of a dangerous pressure differential on the can.

The force on the pressure pad 147 tends to press the pad downwardly into the can 139, thus forcing the edging material upwardly through the wand 144 to flow to and through the edger when the valve thereof is open. At the same time, the air pressure in the tank maintains the gum rubber seals 149 and in tight sliding relation with the can and the wand as the pad moves downwardly into the can, and this, in turn, prevents drying of the material by the air, and also prevents the air from working around the pad and into the edging material.

As the edging material 140 in the can 139 is consumed over a period of use, the pressure pad 147 moves progressively lower in the can and approaches the bottom thereof. Preferably, the upper end portion of the actuating rod 150, above the cylinder 157, is marked to provide an indication of the level of the remaining material in the can, and thereby indicates when a new can is needed.

When this occurs, the tank is depressurized, the cover 131 is removed, the pressure pad 147 is raised out of the nearly empty can in the tank, and the new can is put in the tank in place of the nearly empty can. To facilitate this operation, the actuating rod 150 is formed with an air passage 159 extending from a quickconnect coupling 160 at its upper end, through the pressure pad 147 and to an outlet 161 below the pressure pad, and a normally closed check valve 162 is provided in the passage to prevent edging material from flowing upwardly therein. This valve is formed by a ball which is urged upwardly by a spring 163 for normally holding the ball in a closed position against a downwardly facing seat so as to close the air passage 159.

When the tank is to be opened, the air line 151 is disconnected from the pressure regulator 152 and attached to the quick-connect fitting 160 to apply air pressure to the passage 159. This opens the check valve 162 so that air is admitted into the can 139 below the pressure pad 147 thereby raising the pad out of the can. Then the cover 131 can be easily removed preparatory to changing the cans.

From the foregoing, it will be seen that the present invention provides a new and improved edger for applying edge coatings to workpieces with an improved sealing action that avoids many of the disadvantages of prior edgers, together with an improved automatic feed control for edging material that is responsive to the passing of workpieces to be edged, and with an improved pumping unit for providing a uniform and reliable supply of edging material to the edger, upon demand. It also will be apparent that, while several preferred embodiments of the invention have been illustrated and described herein, various modifications and changes may be made without departing from the spirit and scope of the invention.

I claim:

1. An edger for applying a coating layer of viscous material to an edge of a workpiece of preselected generally uniform thickness as the workpiece is moved along a preselected path relative to the edger, comprising:

a body adapted to be positioned alongside said path and adjacent the edge to be coated;

a guide surface on said body facing toward said path for sliding engagement with said edge to position said body and the workpiece relative to each other;

a trowel element on said body spaced downstream from said guide surface with respect to the direction of relative movement of the workpiece past said edger;

said trowel element having a portion spaced from said path and from the level of said guide surface to form a gap between the trowel element and the passing edge of the workpiece, and being contoured according to the desired contour of the coating layer to be applied;

means for directing viscous material into coating engagement with the edge to be coated, including an orifice between said guide surface and said trowel element;

a pair of wear-resistant sealing elements disposed on opposite sides of said trowel element for sealing engagement with the workpiece along the opposite sides of said gap;

and resiliently yieldable spring means holding said sealing elements inlaterally spaced relation along opposite sides of said gap, at a normal spacing less than said preselected thickness, for engagement with an interference fit with the workpiece as the latter passes over said trowel element, and supporting said sealing elements to yield resistably away from the workpiece upon engagement therewith, so as to remain pressed tightly against the workpiece on opposite sides of the gap, thereby to confine the viscous material in the gap despite variations in the position, shape and edge configuration of the workpiece.

2. An edger as defined in claim 1 in which said trowel element has a troweling surface of shallow, concave curvature facing toward said path, with opposite edge portions extending outwardly toward said path and terminating in closely spaced relation with the margins of the edge to be coated, said opposite edge portions being spaced apart a distance slightly less than the thickness of the workpiece edge, and in which said sealing elements are the free end portions of resiliently flexible spring strips disposed in generally parallel planes and projecting outwardly beyond said trowel element for engagement with the sides of the workpiece adjacent the margins of said edge, said sealing elements being spaced adjacent said gap to receive the workpiece between them with an interference fit, and to spread resiliently apart and be sealingly pressed against said sides as the workpiece passes, said spring means being portions of said strips.

- spring means being the portions of said strips.

4. An edger as defined in claim 3 in which said strips extend beyond said bend and have mounting flanges thereon.

5. An edger as defined in claim 1 in which said seal- 1 ing elements are two resiliently flexible spring strips disposed in generally parallel planes and spaced to receive the workpiece between them with an interference fit, and said trowel element is a shallow, generally U- shaped strip disposed between said strips and having opposite ends substantially level with said guide surface and positioned against said strips, said spring means being portions of said spring strips.

6. An edger as defined in claim 5 in which said U- shaped strip is integrally joined at said ends to said strips.

7. An edger as defined in claim in which said sealing elements are secured to said body with said trowel element between them, and including means for supporting said trowel element on said body independently of said sealing elements.

8. An edger as defined in claim 1 in which said sealing elements and said trowel element are formed integrally from a single sheet of resiliently flexible spring material, having a relatively deep U-shaped bend at one end with the shallow closed portion of said bend constituting said trowel element and the spaced legs of said bend constituting said sealing elements spaced to receive the workpiece between them with an interference fit, and having integral mounting flanges extending in the same direction from one end of said bend in the planes of said legs for attachment to said body.

9. An edger as defined in claim 1 in which said trowel element is a surface that is shaped to the desired contour of the coating to be applied, and having opposite sides that are spaced from said path to leave open sides for-said gap, said sealing elements being mounted along said open sides for movement toward and away from said path between extended and retracted positions, having beveled edges for engagement with the workpiece on opposite sides of the edge thereof to be coated, and being urged toward said extended positions for yieldable engagement with the workpiece by said spring means.

10. An edger as defined in claim 9 in which said sealing elements are blocks of wear-resistant material movably mounted on said body along opposite sides of said gap, said beveled edges being inclined inwardly toward each other and away from said path, from a width greater than the thickness of the workpiece to a widthless than the thickness of the workpiece.

11. An edger as defined in claim 10 in which said blocks are independently urged toward said extended positions by said spring means, in the form of springs disposed alongside said body, and further including retainers secured to said body, said retainers having detents thereon limiting movement of said blocks toward said path and thereby determining the extended positions of said blocks.

12. An edger as defined in claim 11 in which said retainers are slidable along said body and are adjustably secured thereto for adjustment of said extended positions.

13. An edger as defined in claim 1 in which said body comprises a base section adapted to be secured in a fixed position alongside said path, and a movable section mounted on said base section for back and forth movement toward and away from said path between ready and operating positions, said guide surface and said trowel element being mounted on said movable section with the guide surface lying across said path when the movable section is in said ready position, to be engaged by the workpiece and moved away from said path into said operating position, and further including means urging said movable section yieldably toward said ready position, and a valve in said body for controlling the flow of said viscous material through said orifice, said valve being closed when said movable section is'in said ready position and opened by movement of the movable section to said operating position.

14. An edger as defined in claim 13 in which said movable section is supported on said base section for rocking about a pivotal axis between said ready and operating positions, and said sections have closely spaced arcuate surfaces coaxial with said movable section so as to shift relative to each other during such rocking, said surfaces being formed with valve passages that are aligned in said operating position and misaligned in said ready position.

15. An edger as defined in claim 14 in which said base and movable sections are disposed in side-by-side relation, said pivotal. axis is defined by a pin on said basesection projecting laterally therefrom and through said movable section, said arcuate surface on said base section is a wall of a block projecting laterally across the side of said movable section constituting the arcuate surface thereof, and said means yieldably urging the movable section to said ready position includes a spring carried by one of said sections and acting against the other, said movable section being removable from said base section by sliding it laterally off said pin.

16. An edger as defined in claim 15 in which said spring is carried in a recess in said movable section and acts against a second pin projecting laterally from said base section parallel to the first pin, and through a clearance passage in said movable section accommodating said rocking relative to the second pin, said movable section having means thereon for retaining said spring in position to admit said second pin into said clearance passage when the movable section is removed from said base section.

17. An edger as defined in claim 1 in which said means for directing viscous material includes a pumping unit, comprising:

a sealed tank having means therein for supporting an open-ended container with a quantity of said material therein;

a pressure pad for fitting inside said container and having a flexible edge seal for engaging the inside of said container, said pad also having an opening therethrough and an edge seal extending around said opening; I

a wand having one end portion extending through said opening and an opposite end portion open to the outside of said tank;

means for pressurizing the interior of said tank;

and means for applying a force to said pressure pad in addition to the force exerted by the pressure in the tank, to press the pad into the container against the material therein, whereby said edge seals are maintained in contact with the inside of the container and with said wand, while the pad is forced into the container to cause the material to flow out through said wand.

18. An edger as defined in claim 17 in which said pressurizing means include a fitting for admitting gas under pressure intosaid tank.

19. An edger as defined in claim 18 in which said force-applying means include a cylinder having a piston therein and an actuating rod extending from the cylinder into said tank and acting on said pad, and means for delivering actuating fluid under pressure to said cylinder.

20. An edger as defined in claim 19 in which said edge seals are composed of gum rubber.

21. An edger as defined in claim 19 in which said actuating rod has a passage therein for carrying gas under pressure through said pad into the container, and further including means for preventing a flow of said material out through said passage while permitting gas to flow through the passage into the container, and means for connecting the outer end of said passage to a source of gas under pressure for removing the pressure pad from the container.

22. An edger for applying a coating layer of edging material to an edge of a workpiece as the latter is moved along a preselected path relative to the edger, comprising:

a body adapted to be positioned alongside said path and adjacent the edge to be coated;

a guide surface on said body facing toward said path for sliding engagement with the edge to be coated;

a trowel element on said body spaced downstream from said guide surface, and shaped to define a gap of selected shape between the edge and the trowel element;

means for directing the edging material into engagement with the edge to be coated, including an orifice spaced upstream from said troweling element, whereby the material is applied to the edge and then carried past the troweling element to be wiped and smoothed to the desired shape;

a pair of wear-resistant blocks disposed on opposite sides of said gap and mounted on said body for movement between extended positions and retracted positions, said blocks having end portions closing the sides of said gap alongside said troweling element and located in said extended positions to be engaged by workpieces passing said edger;

the adjacent sides of said blocks having sealing surfaces for engaging the workpieces along opposite sides of the edge to be coated;

and means yieldably urging each of said blocks toward its extended position, whereby each block is held tightly against the workpiece to confine the edging material in said gap.

23. An edger as defined in claim 22 in which said sealing surfaces are bevels which are inclined away from each other, said blocks having surfaces facing upstream for engagement with approaching workpieces and defining a flared mouth for cooperating with the workpieces in forcing the blocks toward said retracted positions as each workpiece passes.

24. An edger for applying a coating layer of viscous material to an edge of a workpiece as the latter is moved along a preselected path relative to the edger, comprising:

a base section adapted to be positioned along said path;

a second section mounted on said base section and having one side facing toward said path for engagement therewith, said second section being pivotally supported on a first pin projecting laterally from said base section, for movement toward said path to a ready position and for rocking away from said path to an operating position;

means yieldably urging said second section toward said ready position, comprising a spring carried by said second section and compressed between the latter and a second pin on said base section parallel to the first pin, said second pin projecting through a clearance passage in said base section;

means limiting rocking of said second section when the latter is in said ready position;

means holding said spring in a selected position in said ready position to permit said second section to be slipped onto and off of said pins;

guide means on said second section disposed across said path when the second section is in said ready position, for engagement with the workpieces, and operable in response to such engagement to move the second section to said operating position and hold it therein while the workpiece is in engagement with said guide means;

means for directing viscous edging material into coating engagement with the edge to be coated, including an orifice along said one side of said second section, a first passage in said second section leading to said orifice, a second passage on said base section, and a valve for connecting said passages, said valve being closed when said second section is in said ready position and opened by movement of the second section to said operating position;

and means downstream from said orifice for troweling the edging material to a selected shape on the edge of the workpiece.

25. An edger for applying a coating layer of edging material to an edge of a workpiece as the latter is moved along a preselected path relative to the edger, comprising:

a body adapted to be positioned alongside said path and adjacent the edge to be coated;

a guide surface on said body facing toward said path for sliding engagement with the edge to be coated;

a trowel element on said body spaced downstream from said guide surface, and shaped to define a gap of selected shape between the edge and the trowel element;

means for directing the edging material into engagement with the edge to be coated, including an orifice spaced upstream from said troweling element, whereby the material is applied to the edge and then carried past the troweling element to be wiped and smoothed to the desired shape;

a pair of wear-resistant blocks disposed on opposite sides of said gap and slidably mounted on said body for movement between extended positions and retracted positions by a retainer having a detent determining the extended position of the block, said retainers being adjustably mounted on said body for adjustment of said extended positions relative to said path, said blocks having end portions closing the sides of said gap alongside said troweling element and located by said detents in said extended positions to be engaged by workpieces passing said edger;

the adjacent sides of said blocks having sealing surfaces for engaging the workpieces along opposite sides of the edge to be coated;

and means yieldably urging each of said blocks toward its extended position, whereby each block is held tightly against the workpiece to confine the edging material in said gap.

26. An edger as defined in claim 25 in which said means yieldably urging said blocks toward the extended positions comprise springs compressed between said retainers and said blocks. 

1. An edger for applying a coating layer of viscous material to an edge of a workpiece of preselected generally uniform thickness as the workpiece is moved along a preselected path relative to the edger, comprising: a body adapted to be positioned alongside said path and adjacent the edge to be coated; a guide surface on said body facing toward said path for sliding engagement with said edge to position said body and the workpiece relative to each other; a trowel element on said body spaced downstream from said guide surface with respect to the direction of relative movement of the workpiece past said edger; said trowel element having a portion spaced from said path and from the level of said guide surface to form a gap between the trowel element and the passing edge of the workpiece, and being contoured according to the desired contour of the coating layer to be applied; means for directing viscous material into coating engagement with the edge to be coated, including an orifice between said guide surface and said trowel element; a pair of wear-resistant sealing elements disposed on opposite sides of said trowel element for sealing engagement with the workpiece along the opposite sides of said gap; and resiliently yieldable spring means holding said sealing elements in laterally spaced relation along opposite sides of said gap, at a normal spacing less than said preselected thickness, for engagement with an interference fit with the workpiece as the latter passes over said trowel element, and supporting said sealing elements to yield resistably away from the workpiece upon engagement therewith, so as to remain pressed tightly against the workpiece on opposite sides of the gap, thereby to confine the viscous material in the gap despite variations in the position, shape and edge configuration of the workpiece.
 2. An edger as defined in claim 1 in which said trowel element has a troweling surface of shallow, concave curvature facing toward said path, with opposite edge portions extending outwardly toward said path and terminating in closely spaced relation with the margins of the edge to be coated, said opposite edge portions being spaced apart a distance slightly less than the thickness of the workpiece edge, and in which said sealing elements are the free end portions of resiliently flexible spring strips disposed in generally parallel planes and projecting outwardly beyond said trowel element for engagement with the sides of the workpiece adjacent the margins of saId edge, said sealing elements being spaced adjacent said gap to receive the workpiece between them with an interference fit, and to spread resiliently apart and be sealingly pressed against said sides as the workpiece passes, said spring means being portions of said strips.
 3. An edger as defined in claim 1 in which said trowel element and said sealing elements are formed in one piece as two resiliently flexible spring strips that are disposed in generally parallel planes and are spaced apart adjacent said gap to receive the workpiece between them with an interference fit and to press sealingly against the sides of the workpiece, and a generally U-shaped bend extending between and integrally joining said strips and forming said troweling element, said spring means being the portions of said strips.
 4. An edger as defined in claim 3 in which said strips extend beyond said bend and have mounting flanges thereon.
 5. An edger as defined in claim 1 in which said sealing elements are two resiliently flexible spring strips disposed in generally parallel planes and spaced to receive the workpiece between them with an interference fit, and said trowel element is a shallow, generally U-shaped strip disposed between said strips and having opposite ends substantially level with said guide surface and positioned against said strips, said spring means being portions of said spring strips.
 6. An edger as defined in claim 5 in which said U-shaped strip is integrally joined at said ends to said strips.
 7. An edger as defined in claim 5 in which said sealing elements are secured to said body with said trowel element between them, and including means for supporting said trowel element on said body independently of said sealing elements.
 8. An edger as defined in claim 1 in which said sealing elements and said trowel element are formed integrally from a single sheet of resiliently flexible spring material, having a relatively deep U-shaped bend at one end with the shallow closed portion of said bend constituting said trowel element and the spaced legs of said bend constituting said sealing elements spaced to receive the workpiece between them with an interference fit, and having integral mounting flanges extending in the same direction from one end of said bend in the planes of said legs for attachment to said body.
 9. An edger as defined in claim 1 in which said trowel element is a surface that is shaped to the desired contour of the coating to be applied, and having opposite sides that are spaced from said path to leave open sides for said gap, said sealing elements being mounted along said open sides for movement toward and away from said path between extended and retracted positions, having beveled edges for engagement with the workpiece on opposite sides of the edge thereof to be coated, and being urged toward said extended positions for yieldable engagement with the workpiece by said spring means.
 10. An edger as defined in claim 9 in which said sealing elements are blocks of wear-resistant material movably mounted on said body along opposite sides of said gap, said beveled edges being inclined inwardly toward each other and away from said path, from a width greater than the thickness of the workpiece to a width less than the thickness of the workpiece.
 11. An edger as defined in claim 10 in which said blocks are independently urged toward said extended positions by said spring means, in the form of springs disposed alongside said body, and further including retainers secured to said body, said retainers having detents thereon limiting movement of said blocks toward said path and thereby determining the extended positions of said blocks.
 12. An edger as defined in claim 11 in which said retainers are slidable along said body and are adjustably secured thereto for adjustment of said extended positions.
 13. An edger as defined in claim 1 in which said body comprises a base section adapted to be secured in a fixed position alongside said path, and a movable section mounted on said base section for back and forth movement toward and away from said path between ready and operating positions, said guide surface and said trowel element being mounted on said movable section with the guide surface lying across said path when the movable section is in said ready position, to be engaged by the workpiece and moved away from said path into said operating position, and further including means urging said movable section yieldably toward said ready position, and a valve in said body for controlling the flow of said viscous material through said orifice, said valve being closed when said movable section is in said ready position and opened by movement of the movable section to said operating position.
 14. An edger as defined in claim 13 in which said movable section is supported on said base section for rocking about a pivotal axis between said ready and operating positions, and said sections have closely spaced arcuate surfaces coaxial with said movable section so as to shift relative to each other during such rocking, said surfaces being formed with valve passages that are aligned in said operating position and misaligned in said ready position.
 15. An edger as defined in claim 14 in which said base and movable sections are disposed in side-by-side relation, said pivotal axis is defined by a pin on said base section projecting laterally therefrom and through said movable section, said arcuate surface on said base section is a wall of a block projecting laterally across the side of said movable section constituting the arcuate surface thereof, and said means yieldably urging the movable section to said ready position includes a spring carried by one of said sections and acting against the other, said movable section being removable from said base section by sliding it laterally off said pin.
 16. An edger as defined in claim 15 in which said spring is carried in a recess in said movable section and acts against a second pin projecting laterally from said base section parallel to the first pin, and through a clearance passage in said movable section accommodating said rocking relative to the second pin, said movable section having means thereon for retaining said spring in position to admit said second pin into said clearance passage when the movable section is removed from said base section.
 17. An edger as defined in claim 1 in which said means for directing viscous material includes a pumping unit, comprising: a sealed tank having means therein for supporting an open-ended container with a quantity of said material therein; a pressure pad for fitting inside said container and having a flexible edge seal for engaging the inside of said container, said pad also having an opening therethrough and an edge seal extending around said opening; a wand having one end portion extending through said opening and an opposite end portion open to the outside of said tank; means for pressurizing the interior of said tank; and means for applying a force to said pressure pad in addition to the force exerted by the pressure in the tank, to press the pad into the container against the material therein, whereby said edge seals are maintained in contact with the inside of the container and with said wand, while the pad is forced into the container to cause the material to flow out through said wand.
 18. An edger as defined in claim 17 in which said pressurizing means include a fitting for admitting gas under pressure into said tank.
 19. An edger as defined in claim 18 in which said force-applying means include a cylinder having a piston therein and an actuating rod extending from the cylinder into said tank and acting on said pad, and means for delivering actuating fluid under pressure to said cylinder.
 20. An edger as defined in claim 19 in which said edge seals are composed of gum rubber.
 21. An edger as defined in claim 19 in which said actuating rod has a passage therein for carrying gas under pressuRe through said pad into the container, and further including means for preventing a flow of said material out through said passage while permitting gas to flow through the passage into the container, and means for connecting the outer end of said passage to a source of gas under pressure for removing the pressure pad from the container.
 22. An edger for applying a coating layer of edging material to an edge of a workpiece as the latter is moved along a preselected path relative to the edger, comprising: a body adapted to be positioned alongside said path and adjacent the edge to be coated; a guide surface on said body facing toward said path for sliding engagement with the edge to be coated; a trowel element on said body spaced downstream from said guide surface, and shaped to define a gap of selected shape between the edge and the trowel element; means for directing the edging material into engagement with the edge to be coated, including an orifice spaced upstream from said troweling element, whereby the material is applied to the edge and then carried past the troweling element to be wiped and smoothed to the desired shape; a pair of wear-resistant blocks disposed on opposite sides of said gap and mounted on said body for movement between extended positions and retracted positions, said blocks having end portions closing the sides of said gap alongside said troweling element and located in said extended positions to be engaged by workpieces passing said edger; the adjacent sides of said blocks having sealing surfaces for engaging the workpieces along opposite sides of the edge to be coated; and means yieldably urging each of said blocks toward its extended position, whereby each block is held tightly against the workpiece to confine the edging material in said gap.
 23. An edger as defined in claim 22 in which said sealing surfaces are bevels which are inclined away from each other, said blocks having surfaces facing upstream for engagement with approaching workpieces and defining a flared mouth for cooperating with the workpieces in forcing the blocks toward said retracted positions as each workpiece passes.
 24. An edger for applying a coating layer of viscous material to an edge of a workpiece as the latter is moved along a preselected path relative to the edger, comprising: a base section adapted to be positioned along said path; a second section mounted on said base section and having one side facing toward said path for engagement therewith, said second section being pivotally supported on a first pin projecting laterally from said base section, for movement toward said path to a ready position and for rocking away from said path to an operating position; means yieldably urging said second section toward said ready position, comprising a spring carried by said second section and compressed between the latter and a second pin on said base section parallel to the first pin, said second pin projecting through a clearance passage in said base section; means limiting rocking of said second section when the latter is in said ready position; means holding said spring in a selected position in said ready position to permit said second section to be slipped onto and off of said pins; guide means on said second section disposed across said path when the second section is in said ready position, for engagement with the workpieces, and operable in response to such engagement to move the second section to said operating position and hold it therein while the workpiece is in engagement with said guide means; means for directing viscous edging material into coating engagement with the edge to be coated, including an orifice along said one side of said second section, a first passage in said second section leading to said orifice, a second passage on said base section, and a valve for connecting said passages, said valve being closed when said second section is in said ready position and opened by movement of thE second section to said operating position; and means downstream from said orifice for troweling the edging material to a selected shape on the edge of the workpiece.
 25. An edger for applying a coating layer of edging material to an edge of a workpiece as the latter is moved along a preselected path relative to the edger, comprising: a body adapted to be positioned alongside said path and adjacent the edge to be coated; a guide surface on said body facing toward said path for sliding engagement with the edge to be coated; a trowel element on said body spaced downstream from said guide surface, and shaped to define a gap of selected shape between the edge and the trowel element; means for directing the edging material into engagement with the edge to be coated, including an orifice spaced upstream from said troweling element, whereby the material is applied to the edge and then carried past the troweling element to be wiped and smoothed to the desired shape; a pair of wear-resistant blocks disposed on opposite sides of said gap and slidably mounted on said body for movement between extended positions and retracted positions by a retainer having a detent determining the extended position of the block, said retainers being adjustably mounted on said body for adjustment of said extended positions relative to said path, said blocks having end portions closing the sides of said gap alongside said troweling element and located by said detents in said extended positions to be engaged by workpieces passing said edger; the adjacent sides of said blocks having sealing surfaces for engaging the workpieces along opposite sides of the edge to be coated; and means yieldably urging each of said blocks toward its extended position, whereby each block is held tightly against the workpiece to confine the edging material in said gap.
 26. An edger as defined in claim 25 in which said means yieldably urging said blocks toward the extended positions comprise springs compressed between said retainers and said blocks. 